Assessing Spatial and Temporal Distribution

of Sediment, Nitrogen and Phosphorous

Loading in the Missouri River Basin (MORB)

Zhonglong Zhang, PhD, PE, May Wu, PhD

LimnoTech, Environmental Laboratory,

ERDC, Vicksburg, MS

Argonne National Laboratory, Lemont, IL

2015 SWAT Conference at Purdue University

Courtesy of USACE

Outline

Missouri River Basin (MORB) basics

Baseline SWAT model/calibration results

Future Bioenergy Production (BT2) scenario

analysis

Summary

Nation’s longest (2,300 miles) from Three Forks, MT to

St. Louis, MO.

Basin drains 530,000 mi2 – 1/6 of the US

10 States and 2 Canadian Provinces

Missouri River Basin (MoRB) -

Basics

Elevation range –

400 to 14,000 feet

12 million people –

mostly in lower

portion of Basin

MORB Land Use

51% rangeland

25% cropland

9% forest

6% hay and pasture

4% barren

3% urban

2% Canada

MORB Climate

Mean annual minimum temps ranged from 45 OF

Mean annual maximum temps ranged from 35 to

>60 OF

Mean annual total precipitation ranges from 14

in/yr (NW portion) to 41 in/yr

Courtesy of USGS

MORB Hydrology

25% Contribution

45% Contribution

15% Contribution

Six major mainstem reservoirs

► Fort Peck (Fort Peck Dam)

► Sakakawea (Garrison Dam)

► Oahe (Oahe Dam)

► Sharpe (Big Bend Dam)

► Francis Case (Fort Randall Dam)

► Lewis and Clark (Gavin’s Point Dam)

Authorized purposes: flood control, navigation,

irrigation, hydropower, water supply, fish and

wildlife, water quality, and recreation.

Six large dams have altered the river’s natural

flow.

Missouri River Mainstem Reservoir

System

Fort Peck

Oahe Big Bend

Fort Randall

Gavins Point

Garrison

Montana

North

Dakota

Wyoming

Nebraska

Kansas

Missouri

Iowa

SouthDakota

Colorado

USACE Omaha District

Reservoirs - regulated

Overall Objectives

Quantify relationships between increased biofuel

production, land conversion, and water quality

Develop an appropriate watershed model to link

landscape changes associated with increased

bioenergy production and their impacts on water

quality.

► Conducting an assessment of baselines

► Estimating changes in water quality (sediment and

nutrient loadings) associated with increased biofuel

feedstock production to meet projected targets set by

the energy goal.

Why SWAT?

Water quality Plant/biomass

SedimentHydrology

Management

practices

MORB SWAT Models

(Courtesy of Omaha District)

St. Louis

Sioux City

UMORB: 163 subbasins

LMORB: 144 subbasins

SWAT Model Inputs

Spatial data► Digital Elevation Model (DEM)

► 8-digit Hydrologic Unit Code (HUC)

► Stream network (RF1)

► Land use and land cover (CDL 2007-2010)

► Soil (STATSGO)

► Tillage practices

► Fertilizer application

► Reservoirs

► Atmospheric deposition

► Point Sources

Time series data► Precipitation and temperature (1990-2009)

► Observed gauge data for the calibration and validation (1990-2009)

Model Calibration/Validation Sites

Model Calibration/Validation Results

0

500

1000

1500

2000

2500

3000

Jan-91 Jan-93 Jan-95 Jan-97 Jan-99 Jan-01 Jan-03 Jan-05 Jan-07 Jan-09

Mo

nth

ly F

low

(cm

s)

USGS STATID: 06486000

Observed

Modeled

0

200

400

600

800

1000

1200

1400

1600

1800

2000

1991 1993 1995 1997 1999 2001 2003 2005 2007

An

nu

al

Flo

w (

cm

s)

USGS STATID: 06486000

Observed

Modeled

0

1000

2000

3000

4000

5000

6000

7000

1991 1993 1995 1997 1999 2001 2003 2005 2007

An

nu

al

Flo

w (

cm

s)

USGS STATID: 06935965

Observed

Modeled

0

2000

4000

6000

8000

10000

12000

14000

16000

18000

Jan-91 Jan-93 Jan-95 Jan-97 Jan-99 Jan-01 Jan-03 Jan-05 Jan-07 Jan-09

Mo

nth

ly F

low

(cm

s)

USGS STATID: 06935965

Observed

Modeled

Model Calibration/Validation Results

0

5

10

15

20

25

1991 1993 1995 1997 1999 2001 2003 2005 2007

TS

S (

ton

s/y

r)M

illio

ns

USGS STATID: 06486000

Observed

Modeled

0

1

2

3

4

5

6

Jan-91 Jan-93 Jan-95 Jan-97 Jan-99 Jan-01 Jan-03 Jan-05 Jan-07 Jan-09

TS

S (

ton

s/m

on

th)

Mill

ions

USGS STATID: 06486000

Observed

Modeled

0

20

40

60

80

100

120

140

160

180

200

1991 1993 1995 1997 1999 2001 2003 2005 2007

TS

S (

ton

s/y

r)M

illio

ns

USGS STATID: 06935965

Observed

Modeled

0

10

20

30

40

50

60

70

Jan-91 Jan-93 Jan-95 Jan-97 Jan-99 Jan-01 Jan-03 Jan-05 Jan-07 Jan-09

TS

S (

ton

s/m

on

th)

Mill

ions

USGS STATID: 06935965

Observed

Modeled

Model Calibration/Validation Results

0

10

20

30

40

50

60

70

80

90

Jan-91Jan-93Jan-95Jan-97Jan-99Jan-01Jan-03Jan-05Jan-07Jan-09

TP

(kg

/mo

nth

)M

illio

ns

USGS STATID: 06935965

Observed

Modeled

Model Calibration/Validation Results

Distributions of Modeled Sediment,

Nitrogen, and Phosphorus Loadings

Impacts of Land Use Change on

Water QualityProjected Land Use Changes Involving Four Major Crops

Impacts of Land Use Change on

Water QualityProjected Land Use Changes Involving Four Major Crops

Impacts of Land Use Change on

Water Quality

Comparison of Sediment, Nitrogen, and

Phosphorus Loadings

and Potential Water Quality Impacts

Summary Two SWAT models were developed and used to quantify

the magnitudes of sediment, nitrogen, and phosphorus

loading responses to historical land uses and projected

land use changes within the MORB.

Projected land use conversions in the MORB could have

modest impacts on sediment and nutrient exports from

the basin, will add additional nutrients into the

Mississippi River if not accompanied by conservation

measures.

The study identified subbasins with the highest nutrient

and sediment loss. These hot spots need to be further

investigated and mitigated by adopting land use change

practice and other BMPs.